A porous media ventless thrust bearing seal is disclosed. The porous media thrust bearing may include a primary porous media thrust bearing also serving as a seal ring including porous media positioned over a plenum and a port connected to the plenum, and conductive passages for communicating pressurized fluid to the plenums through the ports of the primary ring. The porous media ventless thrust bearing may also include a treated process gas supplied to a port which is closest to the untreated process gas, at a pressure which is higher than the untreated process gas. An inert gas (or fluid in a liquid state) may be supplied to the remaining port, at a pressure which is the same as the untreated process gas. A certain amount of treated process gas may flow into the untreated process gas, and may prevent the untreated gas from entering the porous media seal.